The effectiveness of different buffer widths for protecting water quality and macroinvertebrate and periphyton assemblages of headwater streams in Maine, USA

2010 ◽  
Vol 67 (1) ◽  
pp. 177-190 ◽  
Author(s):  
Ethel Wilkerson ◽  
John M. Hagan ◽  
Andrew A. Whitman
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Small Sample Size ◽  
Specific Conductivity ◽  
Soluble Reactive Phosphorus ◽  
Timber Harvesting ◽  
Small Sample ◽  
Small Scale ◽  
Treatment Groups ◽  
Partial Harvesting

We evaluated the effect of timber harvesting on water quality and macroinvertebrate and periphyton assemblages in first-order streams in Maine, USA. Fifteen streams were assigned to one of five treatments: clearcutting without a stream buffer, clearcutting with 11 m buffers, clearcutting with 23 m buffers, partial harvesting with no designated buffer, and unharvested controls. Harvest blocks on both sides of the stream were 6 ha and partial harvesting within buffers was allowed. Specific conductivity, pH, dissolved oxygen, turbidity, and soluble reactive phosphorus did not change significantly for 3 years after harvesting in all treatments. Unbuffered streams had significantly elevated concentrations of chlorophyll a as well as increased abundance of algal feeding organisms (Diperta Cricotopus and Diptera Psectrocladius ). Streams with 11 m buffers had substantial (10-fold) but nonsignificant increases in chlorophyll a. No other significant changes were detected in other treatment groups. In all treatment groups, the dominant taxa (periphyton Achnanthes minutissimum and macroinvertebrate Chironomidae) are adapted to disturbed environments. We attribute the limited harvest-induced changes to lack of soil disturbance within 8 m of the stream, the small (≤40%) proportion of watersheds harvested, and the resilient nature of aquatic organisms. However, small-scale changes may not be detected due to the small sample size, an inherent limitation of field-based studies.

A comparison of some small-scale tests for bread-making quality used in wheat breeding

1980 ◽  
Vol 95 (1) ◽  
pp. 29-34 ◽  
Author(s):  
J. A. Blackman ◽  
A. A. Gill
Keyword(s):  
Protein Quality ◽  
Small Sample Size ◽  
Sodium Dodecyl ◽  
Wheat Breeding ◽  
Small Sample ◽  
Small Scale ◽  
Loaf Volume ◽  
Bread Making ◽  
Wheat Varieties ◽  
Sedimentation Volume

SummaryTwenty-five winter wheat varieties and breeders' lines including hard and soft texture, good or poor bread and biscuit-making types were grown at two locations in the U.K. in 1977 to provide the test samples. Small-scale tests of bread-making quality including extensometer, sodium dodecyl sulphate (SDS) sedimentation volume, residue protein, urea dispersible protein and Pelshenke tests, were compared with loaf volumes and loaf scores.Averaged over the two sites, a modified extensometer test and the SDS test gave the closest correlation with loaf volume and loaf score and were only poorly correlated with Hagberg Falling Number and percentage protein. The SDS test gave the closest correlation between sites followed by the extensometer readings; loaf volume and score had much lower values. The SDS values and extensometer readings give a better measure of the genetic differences in protein quality of varieties than loaf volume and score, being less affected by growing conditions. With its small sample size and high throughput, the SDS sedimentation volume is likely to be the most useful screening test for wheat breeding programmes.

scholarly journals Impacts of drying and reflooding on water quality of a tropical semi-arid reservoir during an extended drought event

2019 ◽  
Vol 31 ◽  
Author(s):  
Jéssica Nayara de Carvalho Leite ◽  
Vanessa Becker
Keyword(s):  
Water Quality ◽  
Electrical Conductivity ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Algal Biomass ◽  
Soluble Reactive Phosphorus ◽  
Drought Event ◽  
Reactive Phosphorus ◽  
Semi Arid

Abstract Aim The aim of this study was to analyze the water quality of a tropical, semi-arid reservoir after a reflooding. In terms of impact on water quality after a drought event, it is expected that there will be improvements with the reflooding. Less algal biomass, increased water transparency, decreased turbidity and low nutrient concentration. Methods This study was performed in a tropical, semi-arid man-made lake (Dourado Reservoir), during an extended drought period. This study consisted of a comparison of three distinct periods determined by water accumulation. The limnological variables, including water transparency, turbidity, electrical conductivity, pH, total phosphorus, soluble reactive phosphorus, and chlorophyll-a were analyzed. A principal component analysis (PCA) was also performed to verify the patterns of the variables in relation to the sample units in the studied periods. Results After water renewal, there was an expressive reduction in chlorophyll-a. Electrical conductivity, pH, and turbidity variables also reduced after the reflooding, indicating an improvement in water quality. There was no reduction in total phosphorus and soluble reactive phosphorus after the reflooding compared to the previous periods. Conclusions The significant reduction in algal biomass after reflooding in Dourado indicates water quality improvement in terms of eutrophication due to the change of the trophic state from eutrophic to mesotrophic.

A critical evaluation of integrated care: a case study of the supported discharge service

2019 ◽  
Vol 27 (2) ◽  
pp. 141-152 ◽  
Author(s):  
Rachel Louise Ware
Keyword(s):  
Patient Satisfaction ◽  
Integrated Care ◽  
Patient Outcomes ◽  
Small Sample Size ◽  
Critical Evaluation ◽  
Small Sample ◽  
Small Scale ◽  
Discharge Process ◽  
Content Type

Purpose The purpose of this paper is to evaluate the Supported Discharge Service as a case study of integrated care. The paper will critically evaluate integrated care with regard to patient outcomes, patient satisfaction and cost and productivity. Design/methodology/approach A retrospective mixed methods case study design was adopted utilising patient satisfaction questionnaires, therapy outcome measure and a performance dashboard to measure improvements in patient satisfaction, patient outcomes and cost and productivity. Findings Measured improvements were observed in the integrated discharge process and analysis of the findings demonstrated a statistically significant improvement in patient outcomes, high levels of patient satisfaction and improved productivity subsequently leading to financial savings. Research limitations/implications Due to convenience sampling, the small sample size and a short time frame when analysing patient outcomes, the generalisability of results is limited. Despite this, with integrated care being polymorphous the findings can be utilised to develop theoretical principles to make assertions about integration (Wikfeldt, 1993). Originality/value This paper draws on the importance of integration as the principal driver of reform within the healthcare system. Even though on a small scale, the case study provides evidence to support the use of integration to improve patient outcomes, patient satisfaction and financial savings.

Negative effects of self-help materials: three explorative studies

2015 ◽  
Vol 8 ◽  
Author(s):  
Mark Papworth ◽  
Aileen Ward ◽  
Karen Leeson
Keyword(s):  
Best Practice ◽  
Clinical Presentation ◽  
Small Sample Size ◽  
Postal Survey ◽  
Small Sample ◽  
Small Scale ◽  
Structured Interviews ◽  
Negative Effects ◽  
Self Help ◽  
Training Need

AbstractWithin the field of adult mental health, self-help is now a pivotal treatment modality. However, earlier research indicates that some individuals react negatively to this. Through three, small-scale studies, this paper explores both clinicians’ experience of harm in patients as a response to self-help materials as well as patients’ own reports. In Study 1, a postal survey was administrated to clinicians; in Study 2, semi-structured interviews were conducted with clinicians; and in Study 3, patients were sent a postal survey. Over 18% of clinicians indicated that they had experienced self-help materials resulting in harm to patients. The interviews uncovered four main themes: the patients’ clinical presentation, how the materials were presented within the therapeutic contact, certain personality characteristics in patients, and the characteristics of some materials. Between 12% and 24% of patients reported experience of negative effects (depending upon how this is defined), although the latter finding is limited by a small sample size. Proposals are made that are linked to best practice and it is suggested that there is a generic training need for clinicians in materials’ use.

scholarly journals Is stereotactic radiotherapy equivalent to metastasectomy in patients with pulmonary oligometastases?

2019 ◽  
Vol 29 (4) ◽  
pp. 544-550 ◽  
Author(s):  
Shuangjiang Li ◽  
Shihong Nie ◽  
Zhiping Li ◽  
Guowei Che
Keyword(s):  
Small Sample Size ◽  
Disease Free Survival ◽  
Small Sample ◽  
Treatment Groups ◽  
Evidence Strength ◽  
Significant Difference ◽  
Choice Of Treatment ◽  
Size Heterogeneity ◽  
Study Type

Summary A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether stereotactic body radiotherapy (SBRT) was equivalent to metastasectomy in patients with pulmonary oligometastases arising from solid tumours. Altogether, 1612 papers were found using the reported search, of which 5 cohort studies derived from 4 patient populations represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. All 5 studies demonstrated no significant difference in post-treatment overall survival, disease-free survival or local control between SBRT and metastasectomy for pulmonary oligometastases. One of the 5 studies showed a significantly decreased rate of severe complications among the patients treated with SBRT. The other papers reported higher rates of complications in the SBRT groups, invariably due to radiation, but with uncertain clinical significance. The evidence strength of these findings may be largely attenuated due to the small sample size, heterogeneity of SBRT protocols and incomparable follow-up periods between the 2 treatment groups. The selection criteria for the choice of treatment were not stated. We conclude, based on limited evidence, that SBRT has equivalent outcomes to metastasectomy in the treatment of patients with pulmonary oligometastases.

scholarly journals P336 Association between the prior duration of remission and efficacy outcomes in patients with Ulcerative Colitis treated with tofacitinib 10 mg twice daily who were in stable remission and either dose-reduced to tofacitinib 5 mg twice daily or remained on 10 mg twice daily: 6-month data from the double-blind, randomised RIVETING study

2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S361-S362
Author(s):  
M C Dubinsky ◽  
G R D’Haens ◽  
W J Sandborn ◽  
S C Ng ◽  
J Panés ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Dose Reduction ◽  
Small Sample Size ◽  
Small Sample ◽  
Open Label ◽  
Double Blind ◽  
Treatment Groups ◽  
Mayo Score ◽  
Remission Duration ◽  
To Receive

Abstract Background Tofacitinib is an oral, small molecule JAK inhibitor for the treatment of ulcerative colitis (UC). RIVETING (NCT03281304) is an ongoing, double-blind, randomised, parallel-group study designed to evaluate the efficacy and safety of dose reduction to tofacitinib 5 mg twice daily (BID) vs remaining on 10 mg BID in patients (pts) with UC in stable remission on tofacitinib 10 mg BID maintenance therapy. Eligible pts had received tofacitinib 10 mg BID for ≥2 consecutive years in an open-label, long-term extension study (NCT01470612), and had been in stable remission for ≥6 months (M) and corticosteroid-free for ≥4 weeks prior to enrolment.1 We aimed to evaluate the association between the duration of remission prior to enrolment into RIVETING and the efficacy of tofacitinib 5 and 10 mg BID. Methods Pts who were in partial Mayo score (PMS) remission (a PMS of ≤2 with no individual subscore >1, and a rectal bleeding subscore of 0) at RIVETING baseline were included in this analysis. Pts were randomised to dose-reduce to tofacitinib 5 mg BID or remain on 10 mg BID. We evaluated efficacy endpoints at Month 6 in RIVETING, stratified by duration of PMS remission (0–12, 12–24, 24–36, 36–48, >48 M) at RIVETING baseline. Results At RIVETING baseline, 139 of 140 pts were in PMS remission: 69 pts dose-reduced to tofacitinib 5 mg BID and 70 pts remained on tofacitinib 10 mg BID. In both treatment groups, compared with pts with <24M of PMS remission, baseline modified Mayo and total Mayo scores were numerically lower in pts with a PMS remission duration of >24M; these pts also generally had a numerically lower change from baseline modified Mayo and total Mayo scores at Month 6 (Table). At Month 6, following dose reduction to tofacitinib 5 mg BID, PMS remission was maintained in 66.7%, 60.0%, 82.4%, 75.0% and 90.0% of pts with baseline PMS remission durations of 0–12M, 12–24M, 24–36M, 36–48M and >48M, respectively. Corresponding values for pts who continued to receive tofacitinib 10 mg BID were 80.0%, 88.9%, 91.7%, 100.0% and 100.0%. At Month 6, the proportion of pts achieving modified Mayo remission, remission and modified PMS remission was generally higher in pts with baseline PMS remission of >24M vs pts with PMS remission of <24M across treatment groups (Table). Conclusion Following dose reduction from tofacitinib 10 to 5 mg BID, rates of modified Mayo remission, remission and PMS remission were numerically higher in pts with a PMS remission duration of >24M vs pts with <24M of PMS remission duration. The same trend was observed in pts who continued to receive tofacitinib 10 mg BID. These analyses are post hoc and limited by the small sample size. Reference

A randomized, double-blind study comparing corticorelin acetate with dexamethasone in patients with primary malignant glioma who require increased dexamethasone doses to control symptoms of peritumoral brain edema

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 2080-2080 ◽  
Author(s):  
W. R. Shapiro ◽  
L. Mechtler ◽  
L. Cher ◽  
H. Wheeler ◽  
V. Hines ◽  
...  
Keyword(s):  
Small Sample Size ◽  
Study Drug ◽  
Similar Efficacy ◽  
Small Sample ◽  
Double Blind Study ◽  
Karnofsky Performance Score ◽  
Double Blind ◽  
Treatment Groups ◽  
Cerebral Tumors ◽  
Peritumoral Brain Edema

2080 Background: Corticorelin acetate (CrA) is a synthetic peptide of corticotropin-releasing factor, undergoing clinical trials as a treatment for peritumoral edema in patients with cerebral tumors. This study compared CrA therapy vs an increase in dexamethasone (dex) dose (+4 mg) for controlling symptoms in primary glioma patients with a subacute exacerbation. Methods: In addition to their prestudy dex dose, patients were randomized to receive CrA 1 mg bid SC or control (+4 mg dex PO) for 8 weeks. Patients were evaluated at baseline and during weeks 1 and 2 for their neurologic status, Karnofsky Performance Score (KPS), and continuing dex requirements. The primary endpoint was response, defined as no post-baseline increase in dex dose >4 mg for >1 day; stable or improved KPS; and ≥25% improvement in 10-item Neurological Examination Score during weeks 1 and 2. Dex therapy requirements were also evaluated. The study aimed to enroll 120 patients, but was terminated with only 37 patients (20 CrA, 17 control) due to slow recruitment. Results: Formal statistical analyses were not undertaken due to the small sample size. The treatment groups had similar demographic and baseline disease characteristics. Despite the small numbers, the data suggest that CrA treatment had similar efficacy to increased dex: (1) The proportions of responders were similar (CrA 3/20; control 3/17); (2) Comparable proportions of patients completed 8 weeks’ treatment (CrA 16/20; control 12/17); (3) After randomization of blinded study drug (CrA or dex 4 mg), dex dosing remained stable for most patients in each arm (CrA 12/20; control 11/17); (4) The mean daily dex dose was 3 mg in the CrA arm and 7 mg in the control arm. There was a lower incidence of cushingoid symptoms in the CrA arm (CrA 1/20, control 3/17). Patients in the CrA arm reported more injection site erythema and flushing vs. the control arm. CrA was well tolerated and no patient withdrew from the trial because of CrA side effects. Conclusions: CrA may be of value in managing patients with cerebral tumors who have subacute exacerbations of their symptoms, without needing to increase their dex dose. [Table: see text]

scholarly journals MISSING VALUE IMPUTATION VIA GRAPH COMPLETION IN QUESTIONNAIRE SCORES FROM PERSONS WITH DEMENTIA

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S972-S972
Author(s):  
Chen Kan ◽  
Won Hwa Kim ◽  
Ling Xu ◽  
Noelle L Fields
Keyword(s):  
Missing Data ◽  
Statistical Power ◽  
Missing Values ◽  
Small Sample Size ◽  
Small Sample ◽  
Small Scale ◽  
Assessment And Treatment ◽  
Using Data ◽  
Small Sample Sizes ◽  
Clinical Conditions

Abstract Background: Questionnaires are widely used to evaluate cognitive functions, depression, and loneliness of persons with dementia (PWDs). Successful assessment and treatment of dementia hinge on effective analysis of PWDs’ answers. However, many studies, especially pilot ones, are with small sample sizes. Further, most of them contain missing data as PWDs skip some study sessions due to their clinical conditions. Conventional imputation strategies are not well-suited as bias will be introduced because of insufficient samples. Method: A novel machine learning framework was developed based on harmonic analysis on graphs to robustly handle missing values. Participants were first embedded as nodes in the graph with edges derived by their similarities based on demographic information, activities of daily living, etc. Then, questionnaire scores with missing values were regarded as a function on the nodes, and they were estimated based on spectral analysis of the graph with a smoothness constraint. The proposed approach was evaluated using data from our pilot study of dementia subjects (N=15) with 15% data missing. Result: A few complete variables (binary or ordinal) were available for all participants. For each variable, we randomly removed 5 scores to mimic missing values. With our approach, we could recover all missing values with 90% accuracy on average. We were also able to impute the actual missing values in the dataset within reasonable ranges. Conclusion: Our proposed approach imputes missing values with high accuracy despite the small sample size. The proposed approach will significantly boost statistical power of various small-scale studies with missing data.

scholarly journals Using Genome-Wide Association Study to Identify Genes and Pathways associated with Hypersensitivity Pneumonitis

2020 ◽  
Author(s):  
Ling Wang ◽  
Melissa May Millerick ◽  
Kenneth D. Rosenman ◽  
Yuehua Cui ◽  
Bruce Uhal ◽  
...  
Keyword(s):  
Hypersensitivity Pneumonitis ◽  
Genome Wide Association Study ◽  
Excision Repair ◽  
Small Sample Size ◽  
Enrichment Analysis ◽  
Small Sample ◽  
Small Scale ◽  
Control Group ◽  
P Value ◽  
Pathway Enrichment Analysis

AbstractBackgroundHypersensitivity Pneumonitis (HP) is an interstitial lung disease caused by an immune response to the inhalation of antigens. Since only a small proportion of individuals exposed to HP-related antigens develop the disease, a genetic variation may play a role in disease development.MethodsIn this small-scale study, 24 patients diagnosed with HP were matched with control group who shared the patient’s environment and were exposed to the same HP-associated antigens. Logistic regression was employed to identify Single-Nucleotide Polymorphisms (SNPs) associated with HP. Next genes associated with HP were identified using sequence kernel association test (SKAT) analysis. Last, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Oncology (GO) enrichment analysis were employed to find HP signaling pathways using SNPs coded on genes and on non-coding genes, respectively.ResultsGiven the small sample size, no single SNPs or genes were identified to be significantly associated with HP after adjustment for multiple testing. After P-value adjustment, the KEGG and GO pathway enrichment analysis identified 11 and 20 significant pathways respectively using SNPs coded on genes. Among these pathways, Cell cycle, Proteasome and Base excision repair had previously reported to be associated with lung function.ConclusionThis is the first GWAS study identifying genetic factors associated with HP. Although no significant associations at SNPs/gene level were identified, there were significant pathways that are identified associated with HP which need further investigation in large cohorts.

scholarly journals Analysis of the MANAGE Drain Concentration Database to Evaluate Agricultural Management Effects on Drainage Water Nutrient Concentrations

2019 ◽  
Vol 62 (4) ◽  
pp. 929-939
Author(s):  
Allan J. Hertzberger ◽  
Cameron M. Pittelkow ◽  
R. Daren Harmel ◽  
Laura E. Christianson
Keyword(s):  
Water Quality ◽  
Regression Analysis ◽  
Nutrient Management ◽  
Small Sample Size ◽  
Application Rate ◽  
Drainage Water ◽  
Small Sample ◽  
Nutrient Concentrations ◽  
Agricultural Systems ◽  
Nutrient Losses

Abstract. Agricultural systems are substantial contributors of nonpoint-source nitrogen (N) and phosphorus (P) pollution, and loss of dissolved forms of these nutrients is exacerbated in subsurface-drained (tile-drained) landscapes. The majority of reviews summarizing drainage nutrient losses have focused on N and P loads, but closer inspection of drainage concentrations is necessary to more directly link cropping management factors with water quality outcomes. More than 1,500 recently compiled site-years of drainage N and P concentration in the Measured Annual loads from AGricultural Environments (MANAGE) Drain Concentration database were used to analyze the impacts of crop selelction, nutrient management, and tillage type on annual drainage nutrient concentrations. The highest annual flow-weighted mean NO3-N concentrations across the database were from corn, corn and soybean (grown within the same plot in the same year), and soybean site-years (14.0, 13.5, and 12.1 mg L-1, respectively). However, crop selection was not a significant predictor for annual average dissolved reactive phosphorus (DRP) concentrations in drainage. Nitrogen application rates below 75 kg ha-1 for corn did not significantly reduce annual NO3-N concentrations compared to rates of 75 to 149 kg ha-1 or 150 to 224 kg ha-1, although the three largest application rate categories (75 to 149 kg ha-1, 150 to 224 kg ha-1, and >224 kg ha-1, respectively) resulted in significantly increasing NO3-N concentrations. The stepwise regression approach was used to reduce and select predictors to model annual NO3-N and DRP concentrations. Regression analysis of NO3-N concentrations had an overall model R2 of 0.59 (n = 254) and indicated that N application rate had the greatest effect on NO3-N concentrations in corn site-years, followed by fertilizer timing and tillage type. Regression analysis of DRP concentrations had an overall R2 of 0.94, and although the model was less robust due to the small sample size (n = 47), fertilizer timing was most closely correlated with annual DRP concentrations. The MANAGE database will continue to evolve and remain a resource for new exploratory efforts to better understand and reduce nutrient losses from agricultural systems. Keywords: Concentration, Drainage, Nitrogen, Phosphorus, Water quality.

Sign in / Sign up

Export Citation Format

Share Document